University of Virginia Health System

Medical Laboratories

“Quality You Expect, Service You Deserve”

 

LABORATORY MEDICINE UPDATE

February 27, 2006

Urinalysis, reflex culture if indicated

Beginning February 28, 2006 , the Medical Laboratories will offer the following test menu for urines:

  1. Urinalysis – currently offered
  2. Urine Culture – currently offered
  3. Urinalysis, reflex culture if indicated – NEW OPTION

Options 1 and 2 are stand alone tests and may be ordered independently depending on the clinician’s needs.

Option 3 (NEW OPTION) – A urinalysis will be performed. If any of the following criteria are met, a urine culture will be performed without further orders from the physician:

  • Positive Leukocyte Esterase
  • Positive Nitrite
  • >5 White Blood Cells/HPF
  • Any bacteria present

All options will be available for ordering through MIS and Carecast by noon on February 28, 2006 .  Current outpatient test request forms do not have the new option on the form; requests for the new option should be written on the form as “Urinalysis reflex culture if indicated”. The next revision of this form will include a place to mark this option.

 

New PT Reagent

The Hemostasis Laboratory converted to a new PT reagent on February 1st. The reference interval remains the same; 12.5 - 15.2 seconds.

The new ISI value for this PT reagent is 1.30. The geometric mean established for this reference interval is 13.8 seconds. This small change in the ISI from 1.26 to 1.30 will have a minimal difference in the new INR calculated values. Any questions regarding this change should be directed to the Special Coagulation Laboratory at 924-8007 or to the Coagulation Pathology Resident (Pager 1663).

 

Adjusted Reference Intervals

Albumin: The reference interval for albumin has been adjusted to 3.5 – 5.7 g/dL to more accurately reflect data of UVa patients.

Thyroid Autoantibodies: Test systems for thyroid autoantibodies have changed due to a nationwide reagent availability problem.  Sample requirements remain the same. 

The new reference intervals are:

  • Anti-Thyroglobulin                    <40 IU/mL
  • Anti-Thyroid Peroxidase           <35 IU/mL

Growth Hormone: The test system for growth hormone has also changed due to a nationwide reagent availability problem.  Sample requirements remain the same, however the reference interval has changed to 0.06 – 5.00 ng/mL.

 

Vitamin D Assay Moved In-house

 

Beginning February 28, 2006 , the Toxicology Laboratory will begin performing 25-OH vitamin D analyses by liquid chromatography with tandem mass spectrometry (LC-MS/MS).   The use of LC-MS/MS allows determination of both 25-OH vitamin D3 (produced from the naturally occurring vitamin D3 that is made from the skin) and 25-OH vitamin D2 (from some administered forms of the vitamin).  Results will be reported as the individual species and as the sum.  The reference interval (sum) is 25-80 ng/mL SI units: 25-80 µg/L or 62-200 mmol/L).  Values greater than 150 ng/mL are considered toxic and will be reported to the ordering physician immediately as a critical value.

Specimen type is serum (red or gold-topped tube) and the minimum volume required is 0.5 mL serum.  Please contact the Pathology Chemistry Resident (pic 1267) if you have any questions.